Coupling members adapted for attachment to the end of hose or tubing for use in the transfer of fluids under pressure from one point to another are well known in the prior art. Rotatable couplings heretofore available have generally been made by either carefully compressing an annular portion of an outer member of the coupling radially inwardly into a groove of an inner member such that the two are rotatably inter-locked or by placing a releasable locking clip through the outer member of the coupling such that it passes through a portion of an annular groove in the inner member and thereby interlocks the two in rotatable relationship. Hose couplings having externally mounted interlocking devices are shown, for example, in U.S. Pat. No. 1,019,000 issued Feb. 27, 1912 which discloses an externally mounted forked wedge as a means of interlocking hose sections and in U.S. Pat. No. 1,871,421 issued Aug. 9, 1932 which requires complex external studs and machined slots. Other examples are shown in U.S. Pat. No. 1,838,549 issued Dec. 29, 1939 in which a valved coupling requires a coupling externally mounted jaw and in German Pat. No. 1,425,470 issued Nov. 21, 1968 which discloses a socket connection using an externally mounted clip as a means of securing the connector members. Further examples are shown in U.S. Pat. Nos. 3,538,940 issued Nov. 10, 1970 and 3,560,027 issued Feb. 2, 1971, which generally disclose complex coupling assemblies respectively having externally mounted clips and retainment clips as a means of securing mating parts and in U.S. Pat. Nos. 2,772,898 issued Dec. 4, 1956 and 3,523,701 issued Aug. 11, 1970 which respectively disclose an externally mounted retaining clip and spring clip as a means of interlocking mating parts of the coupling. The above noted references generally have the disadvantage of requiring complex machined parts or specialized sealing arrangements because of penetrations made into the internal flow chambers by externally mounted retainment or interlocking devices or in many cases are limited to low pressure operation because of inherent design limitations. None of the above references disclose or suggest a coupling member having concealed retainment means providing a rotatable inter-locked relationship between its member parts that is adapted for attachment to an end or between the ends of a hose or tube used in the conveyance of fluids under pressure nor do they teach a method of providing the secured relationship of the invention as hereinafter described.